1. Field of the Invention.
The invention relates to a device for recovering heat from the soil comprising at least heat-exchanging means for absorbing heat from groundwater and the soil.
2. Description of the Prior Art.
A device of this type for recovering heat from the soil has been used in the art. In this known device a pipe is placed into the soil, whereupon, by using a pump, groundwater which has a higher temperature is pumped upwards from great depths, said heat being subsequently recovered by means of heat-exchanging surfaces. Thus, by taking advantage of the temperature of the groundwater or of the soil, it is possible to obtain considerable savings in the costs for heating buildings, houses, pavements, airports and the like.
A drawback of said devices is that groundwater is removed from the soil, which groundwater is usually discharged through the sewer system. In view of possible environmental disturbances, efforts have been made over the past few years to minimize the removal of groundwater from the soil, so that the aforesaid arrangements are unsuitable for the regular recovering of heat from the soil.
It has recently been proposed to overcome said drawbacks by carrying the pumped-up groundwater back into the soil in another place after having recovered the heat, but this also leads to great objections because of the resultant environmental pollution caused by microbes and the like.